Dosage limiting device

ABSTRACT

An adjustable dosage limiting device includes a member that interfaces to a plunger flange of a syringe and a barrel loop that slides along a barrel of the syringe. A locking mechanism, when engaged, fixes a distance between the member that interfaces to a plunger flange and the barrel loop, and hence, locks the barrel loop in place with respect to the plunger flange. Once locked in place, the adjustable dosage limiting device limits a dosage provided by the syringe based upon a distance between the member that interfaces to a plunger flange and the barrel loop as set by the locking mechanism.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. patent application Ser. No. 16/556,370, filed Aug. 30, 2019 which is a continuation-in-part of U.S. patent application Ser. No. 16/011,772, filed Jun. 19, 2018.

FIELD

This invention relates to the field of medicine and more particularly to a system for limiting dosages administered by a syringe.

BACKGROUND

It is well known in the art of medicine to administer liquid medication using a syringe. For example, a small child may be given a dosage of 3 ml by way of a plastic syringe. The person or caregiver pushes the plunger of the syringe all the way in, then places the tip of the syringe into the liquid medication, then pulls the plunger out until the base of the plunger aligns with a gradient matching the dosage, or in this example, 3 ml. Then, the tip of the syringe is placed in the mouth of the child and the plunger of the syringe is pushed back in, delivering the requisite amount of the medicine.

Unfortunately, this method of administering a liquid medication (or any liquid) suffers from inaccuracies caused by many reason. For example, the caregiver (or person taking the medication) has poor visibility to the gradients due to darkness or poor eyesight or the caregiver does not understand how to correctly meter the dosage, etc. Due to such inaccuracies, the patient (receiver of the liquid) often is provided with too much of the liquid (medication) or too little.

What is needed is a system that will meter the dosage provided from a syringe to an amount required as preset by a person.

SUMMARY

Many users of medication are not familiar with self-medication, especially when the medication is administered with a syringe. Syringes provide a variable amount of medication based upon the amount of medication drawn into the syringe or the amount of medication released from the syringe during administration. When the medication and syringe is provided (e.g. from a pharmacist), the person providing such instructs the user of the medication as to an amount to administer, typically in milliliters. Many users are unfamiliar with metric measurements, many users have capacity issues where their vision is degraded or the memory span too short to remember how to self-administer the medication. The present invention describes a device that can be set by the person providing the medication and locks into place such that, when used in conjunction with the syringe, limits the dosage to that of which is it set and the described device cannot easily be modified to provide a different dosage.

In one embodiment, an adjustable dosage limiting device is disclosed including an elongated connecting member that has a plunger receiving head at a first end for capturing a plunger flange of a plunger of a syringe. A slidable member is slidably interfaced to the elongated connecting member. The slidable member has a lock that, when engaged, holds the slidable member at a preset location on the elongated connecting member. A barrel loop is connected to the slidable member so that the adjustable dosage limiting device limits a dosage provided by the syringe based upon a distance between the plunger receiving head and the barrel loop as during extraction of the plunger, the barrel loop abuts a barrel flange of the syringe, thereby limiting extraction of the plunger of the syringe.

In another embodiment, a method of limiting a dosage provided by a syringe includes moving a slidable member of an adjustable dosage limiting device along an elongated connecting member until a desired preset dosage limit is set then activating a locking mechanism to fix the slidable member to the elongated connecting member at the desired preset dosage limit. Next, the adjustable dosage limiting device is installed on the syringe by installing a plunger receiving head of the adjustable dosage limiting device on a plunger flange of the syringe (the plunger receiving head at a first end of the elongated connecting member) and installing a barrel loop of the adjustable dosage limiting device around a hollow barrel of the syringe (the barrel loop connected to the slidable member of the elongated connecting member). Now, the plunger flange of the syringe is pushed until the plunger of the syringe is fully within the hollow barrel of the syringe and a hollow tip of the syringe is submerged in a liquid. Now, the plunger flange of the syringe is pulled (extracted) until the barrel loop abuts a barrel flange of the syringe, thereby filling a portion of the hollow barrel of the syringe with the preset amount of the liquid as limited by the adjustable dosage limiting device. The hollow tip is placed into a destination and the plunger flange of the syringe is pushed until the plunger of the syringe is fully within the hollow barrel of the syringe, thereby delivering the preset dosage limited by the adjustable dosage limiting device into the destination.

In another embodiment, an adjustable dosage limiting device is disclosed including an elongated connecting member with a plunger receiving head at a first end for capturing a plunger flange of a plunger of a syringe. The plunger receiving head has a back flange connected to the elongated connecting member and a forward slotted flange connected to the elongated connecting member, the forward slotted flange is separated from the back flange by a space sufficient to accept the plunger flange. A flat section of the plunger fits in a slot of the forward slotted flange. A slidable member is slidably interfaced to the elongated connecting member. The slidable member has a lock that, when engaged, holds the slidable member at a preset location on the elongated connecting member. A barrel loop is connected to the slidable member such that, the adjustable dosage limiting device limits a dosage provided by the syringe based upon a settable distance between the plunger receiving head and the barrel loop as during extraction of the plunger, the barrel loop abuts a barrel flange of the syringe, thereby limiting extraction of the plunger of the syringe.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be best understood by those having ordinary skill in the art by reference to the following detailed description when considered in conjunction with the accompanying drawings in which:

FIG. 1 illustrates a perspective view of a syringe of the prior art.

FIG. 2 illustrates a perspective view of a dosage limiting device manufactured for a first dosage amount.

FIG. 3 illustrates a perspective view of a dosage limiting device manufactured for a second dosage amount.

FIG. 4 illustrates a second perspective view of a dosage limiting device manufactured for the first dosage amount.

FIG. 5 illustrates a second perspective view of a dosage limiting device manufactured for the second dosage amount.

FIG. 6 illustrates a perspective view of a dosage limiting device manufactured for the first dosage amount installed on a syringe with the plunger pushed in all the way.

FIG. 7 illustrates a perspective view of a dosage limiting device manufactured for the first dosage amount installed on a syringe with the plunger pulled out as far as allowed by the dosage limiting device.

FIG. 8 illustrates a perspective view of a dosage limiting device manufactured for the second dosage amount installed on a syringe with the plunger pushed in all the way.

FIG. 9 illustrates a perspective view of a dosage limiting device manufactured for the second dosage amount installed on a syringe with the plunger pulled out as far as allowed by the dosage limiting device.

FIG. 10 illustrates a sectional view of an elongated member of a settable dosage limiting device.

FIG. 11 illustrates a plan view of a barrel-capture and locking member of the settable dosage limiting device.

FIG. 12 illustrates a sectional view of a barrel-capture and locking member of the settable dosage limiting device.

FIG. 13 illustrates an exploded sectional view of a syringe and the settable dosage limiting device.

FIG. 14 illustrates a sectional view of the settable dosage limiting device installed on the syringe.

FIG. 15 illustrates an elevational view of the settable dosage limiting device installed on the syringe.

FIG. 16 illustrates a perspective view of the settable dosage limiting device preset for a dosage amount and installed on a syringe with the plunger of the syringe pushed all the way into the syringe.

FIG. 17 illustrates a perspective view of the settable dosage limiting device and the syringe.

DETAILED DESCRIPTION

Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Throughout the following detailed description, the same reference numerals refer to the same elements in all figures.

Referring to FIG. 1 . An exemplary syringe 10 of the prior art is shown. The syringe 10 has a hollow tip 16 for drawing a liquid (e.g. medicine) into the hollow barrel 15 of the syringe 10 and, later, expelling the liquid into a destination (e.g. mouth of the patient). The liquid is drawn into the syringe 10 by first pushing the plunger flange 13 until the plunger seal 14 is all the way into the hollow barrel 15 of the syringe 10, then inserting the hollow tip 16 into the liquid, then pulling the plunger flange 13 out until the plunger seal 14 aligns with a gradient 18 matching the required dosage. To allow finger grips during operation, the syringe 10 has a barrel flange 17. The plunger 12 of a syringe 10 typically has flat sections 19 that improve rigidity.

In practice, syringes 10 provide a range of dosages, in that each typical syringe is capable of providing from a smallest dosage (e.g. 1 ml. or ¼ tsp.) to a largest dosage (e.g. 5 ml. or 1 tsp.).

Referring to FIGS. 2 through 9 , two specific dosage limiting devices 20A/20B are shown. Although it is anticipated that dosage limiting devices 20A/20B be provided for any specific dosage, for clarity reasons, only two sizes of dosage limiting devices 20A/20B are shown in the figures and described. It should also be noted that the exact shape and composition of the two, specific dosage limiting devices 20A/20B is not limited as other shapes and materials will accomplish the same or similar function without veering from the disclosure and claims here within.

In FIGS. 2 through 5 , the two specific dosage limiting devices 20A/20B are shown from the side. Each dosage limiting device 20A/20B has an elongated connecting member 26A/26B. At a first end of the elongated connecting members 26A/26B is a plunger flange receiving head 22A/24A/22B/24B for capturing a plunger flange 13 of the plunger 12 of the syringe 10. In the example shown, each plunger receiving head 22A/24A/22B/24B consists of a back flange 22A/22B and a forward slotted flange 24A/24B separated by a space 23A/23B wide enough to fit the plunger flange 13 of the plunger 12. The plunger flange 13 fits snuggly in the space between the back flange 22A/22B and a forward slotted flange 24A/24B. As the typical plunger 12 has flat sections 19 that improve rigidity, these flat sections 19 fit into the slot 25A/25B.

At a distal second end of the elongated connecting members 26A/26B is a barrel loop 28A/28B. As shown in FIGS. 6 through 9 , in use, the hollow barrel 15 of the syringe 10 is inserted into the barrel loop 28A/28B and the plunger flange 13 of the syringe 10 is inserted into the plunger receiving head 22A/24A/22B/24B. The dosage limiting devices 20A/20B therefore limit the distance that the plunger flange 13 can be extracted from the hollow barrel 15 of the syringe as the barrel loop 28A/28B abuts the barrel flange 17 of the syringe 10.

In some embodiments, each barrel loop 28A/28B has a slit 27A/27B to facilitate capturing the hollow barrel 15 of the syringe 10 within the barrel loops 28A/28B. As one anticipated material from which the dosage limiting devices 20A/20B are made is plastic, by using a pliable and resilient plastic, the barrel loops 28A/28B will open at the slits 27A/27B for ease of installation onto the hollow barrel 15 of the syringe 10.

Note that the length of the elongated connecting member 26A/26B determines the dosage that is administered. For example, the first dosage limiting device 20A has a longer elongated connecting member 26A while the second dosage limiting device 20B has a shorter elongated connecting member 26B.

Operation of the dosage limiting devices 20A/20B are shown in FIGS. 6-9 . In FIG. 6 , the first dosage limiting device 20A mounted on the syringe 10 with the plunger 12 of the syringe 10 pushed in. In FIG. 7 , the first dosage limiting device 20A is shown limiting how far the plunger 12 of the syringe 10 can be pulled out. In this example, when the plunger 12 of the syringe 10 is pulled out, the first dosage limiting device 20A limits extraction to the ¾ tsp. gradient 30A, therefore, in this example, the first dosage limiting device 20A limits the dosage to ¾ tsp.

Now, in FIG. 8 , the second dosage limiting device 20B is mounted on the syringe 10 with the plunger 12 of the syringe 10 pushed in. In FIG. 9 , the second dosage limiting device 20B is shown limiting how far the plunger 12 of the syringe 10 can be pulled out. In this example, when the plunger 12 of the syringe 10 is pulled out, the second dosage limiting device 20B limits extraction to the ½ tsp. gradient 30B, therefore, in this example, the second dosage limiting device 20B limits the dosage to ½ tsp.

Again, the two dosage limiting devices 20A/20B are examples and it is fully anticipated that dosage limiting devices 20A/20B be provided for various sizes of syringes and for any desired dosage in metric (e.g. ml) or English units (e.g. tsp.).

It is fully anticipated that the dosage limiting devices 20A/20B be provided as single items or in packages containing several, either having all the same dosage amounts or different dosage amounts. For example, a package of five dosage limiting devices 20A/20B contains one each dosage limiting device 20A/20B or 1 ml, 2 ml, 3 ml, 4 ml, and 5 ml. It is also anticipated that, in some embodiments, each dosage limiting devices 20A/20B be marked with markings indicating the dosage of such and, in some embodiments a company advertisement is also marked on the dosage limiting devices 20A/20B (e.g., a pharmacy name).

Referring to FIGS. 10-17 , an adjustable dosage limiting device 40 is shown.

The dosage limiting device 20A/20B described prior works fine for fixed dosages, each dosage limiting device 20A/20B limiting dosages to a fixed amount and each one calibrated at manufacture to a fixed limit. These types of fixed dosage limiting devices require, in some applications, a pharmacy (for example) to stock several types of dosage limiting devices 20A/20B. Instead of stocking several dosage limiting devices 20A/20B, one for each anticipated dosage, the adjustable dosage limiting device 40 provides for a settable range of dosage limits. In such, a person such as a pharmacist presets the adjustable dosage limiting device 40 to the proper dosage for the patient, then locks the adjustable dosage limiting device 40 to that dosage. After locking, then installing the adjustable dosage limiting device 40 onto the syringe 10, the adjustable dosage limiting device 40 prevents the plunger flange 13 of the syringe 10 from being withdrawn by more than the preset dosage. After locking, it is difficult to manually overcome the locking mechanism, for example, by hand without tools (e.g. pliers, knife, hammer) and, therefore, it is presumed that the adjustable dosage limiting device 40 will remain at the preset dosage throughout use by the user as it is presumed that the user wishes to administer the correct dosage and, therefore, the user will not use tools to circumvent the locking mechanism.

Although the adjustable dosage limiting device 40 shown in FIGS. 10-17 has a specific locking mechanism 50/52/53 (shown unlocked in FIG. 17 ), any similar or different locking mechanism is equally anticipated and included here within. The intent of the locking mechanism 50/52/53 is to fix a preset relationship between the elongated shaft 54/56 and the sliding member 50. Therefore, the locking mechanism 50/52/53 shown is an example of such and any other locking mechanism that locks the sliding member 50 to the elongated shaft 54/56 is included here within. Examples of such include, but are not limited to, set screws, adhesives, a knob that breaks off after engaging, etc. The adhesive example includes placing a drop of instantly hardening adhesive between the sliding member 50 and the elongated shaft 54/56.

The exemplary adjustable dosage limiting device 40 includes a barrel loop 48 that, when installed, surrounds the hollow barrel 15 (e.g. when no medication is present) of the syringe 10. The barrel loop 48 is connected to or part of a sliding member 50 that, until locked, slides up/down the elongated shafts 54/56. After the locking mechanism 52/53 is closed (locked position) the sliding member 50 becomes stationary along the elongated shafts 54/56, remaining at the pre-set location until forcibly removed, for example, with tools such as knives or pliers. The elongated shaft 54/56 fits within and slides through a space 49 between inner surfaces of the sliding member 50.

The exemplary locking mechanism 52/53 is shown unlocked in FIG. 17 . In the locked position shown in FIGS. 12-16 , the tab 52 of the locking mechanism 52/53 is flush or recessed below a surface of the sliding member 50 so that the locking mechanism 52/53 is not easily defeated. In other embodiments, locking is performed by turning a knob, tightening a set screw, using an adhesive, etc. Also, in the locked position, the wedge 53 of the locking mechanism 52/53 is inserted between legs of the elongated shaft 54/56, thereby exerting pressure between the legs of the elongated shaft 54/56 and inner surfaces of the sliding member 50. In some embodiments, the inner surface of the sliding member 50 that interfaces with the optionally jagged side of the elongated shaft 54/56 is also jagged, such that, when the wedge 53 is inserted between legs of the elongated shaft 54/56, the legs of the elongated shaft 54/56 bow outward and the two jagged surfaces lock onto each other like gears, preventing movement of the elongated shaft 54/56 within the sliding member 50.

At an end of the elongated shafts 54/56 that is distal from the sliding member 50, there is a receiving head 43/45. The receiving head 43/45 captures the plunger flange 13, so that, as the plunger flange 13 is pulled to draw a fluid into the hollow barrel 15 of the syringe 10, the elongated shafts 54/56 pull the sliding member 50 and barrel loop 48 along the hollow barrel 15 of the syringe 10 until the barrel loop 48 abuts the barrel flange 17 of the syringe 10, thereby limiting how far the plunger flange 13 can be extracted and, therefore, the amount of liquid (medication) that is drawn into the hollow barrel 15. In this way, the pharmacist (for example) is able to set a predetermined maximum dosage using the adjustable dosage limiting device 40 so that a patient will administer a proper dosage and not provide a dosage that is more than preset (prescribed).

When the barrel loop 48 is locked onto the elongated shaft 54/56, the distance between the barrel loop 48 and the receiving head 43/45 defines how far the barrel loop 48 is able to travel along the hollow barrel 15 and, therefore, defining the maximum amount of liquid that can be drawn into the hollow barrel 15 during use, thereby limiting the dosage to a pre-set amount.

Equivalent elements can be substituted for the ones set forth above such that they perform in substantially the same manner in substantially the same way for achieving substantially the same result.

It is believed that the system and method as described and many of its attendant advantages will be understood by the foregoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely exemplary and explanatory embodiment thereof. It is the intention of the following claims to encompass and include such changes. 

What is claimed is:
 1. An adjustable dosage limiting device comprising: an elongated connecting member; a plunger receiving head for capturing a plunger flange of a plunger of a syringe, the plunger receiving head is fixed to first end of the elongated connecting member; a slidable member slidably interfaced to the elongated connecting member, the slidable member having a lock, the lock, when engaged, holding the slidable member at a pre-set location on the elongated connecting member, the lock cannot be defeated without a use of a tool; and a barrel loop fixed to the slidable member, the barrel loop for freely sliding across a barrel of the syringe; whereas the adjustable dosage limiting device limits a dosage provided by the syringe based upon a distance between the plunger receiving head and the barrel loop as during extraction of the plunger, the barrel loop abuts a barrel flange of the syringe, thereby limiting extraction of the plunger of the syringe.
 2. The adjustable dosage limiting device of claim 1, wherein the plunger receiving head has a back flange connected to the elongated connecting member and a forward slotted flange connected to the elongated connecting member so that a slot of the slotted flange is adjacent to the elongated member, the forward slotted flange is separated from the back flange by a space sufficient to accept the plunger flange, a flat section of the plunger fitting in a slot of the forward slotted flange.
 3. The adjustable dosage limiting device of claim 1, wherein the barrel loop is tubular to surround a hollow barrel of the syringe.
 4. The adjustable dosage limiting device of claim 3, wherein the barrel loop has a slit for ease of installation on the hollow barrel of the syringe.
 5. The adjustable dosage limiting device of claim 1, further comprising markings on the elongated connecting member.
 6. The adjustable dosage limiting device of claim 5, wherein the markings include a dosage amount.
 7. The adjustable dosage limiting device of claim 5, wherein the markings include an advertisement.
 8. A method of limiting a dosage provided by a syringe, the method comprising: first, installing the adjustable dosage limiting device on the syringe by: installing a plunger receiving head of the adjustable dosage limiting device on a plunger flange of the syringe, the plunger receiving head at a first end of an elongated connecting member; installing a barrel loop of the adjustable dosage limiting device around a barrel of the syringe and onto the elongated connecting member; second, pushing the plunger flange of the syringe until the plunger of the syringe is fully within the hollow barrel of the syringe; third, moving the barrel loop along the elongated connecting member until a desired preset dosage limit is set; and fourth, activating a locking mechanism to fix the barrel loop in position on the elongated connecting member at the desired preset dosage limit after which, the barrel loop is locked to the elongated connecting member and cannot be removed manually.
 9. The method of claim 8, further comprising submerging a hollow tip of the syringe into a liquid; pulling the plunger flange of the syringe, the barrel loop traversing the barrel of the syringe until the barrel loop abuts a barrel flange of the syringe, thereby filling a portion of the barrel of the syringe with the liquid to the preset amount of the liquid as limited by the adjustable dosage limiting device; placing the hollow tip into a destination; and pushing the plunger flange of the syringe until the plunger of the syringe is fully within the barrel of the syringe, thereby delivering the preset dosage limited by the adjustable dosage limiting device into the destination.
 10. The method of claim 8, wherein the plunger receiving head has a back flange connected to the elongated connecting member and a forward slotted flange connected to the elongated connecting member, forward slotted flange is separated from the back flange by a space sufficient to accept the plunger flange, a flat section of the plunger fitting in a slot of the forward slotted flange.
 11. The method of claim 9, wherein the barrel loop has a slit for ease of installation on the barrel of the syringe.
 12. The method of claim 8, further comprising markings on the elongated connecting member of the adjustable dosage limiting device.
 13. The method of claim 12, wherein the markings include a dosage amount.
 14. The method of claim 12, wherein the markings include an advertisement.
 15. An adjustable dosage limiting device comprising: means for attaching to a plunger flange of a syringe; means for slidably interfacing to a barrel of the syringe, the means for slidably interfacing to the barrel of the syringe adjustably interfaced to the means for attaching to the plunger flange; means for fixing a distance between the means for slidably interfacing to the barrel of the syringe and the means for attaching to the plunger flange such that the distance defines a dosage that will be delivered by the syringe.
 16. The adjustable dosage limiting device of claim 15, wherein the means for attaching to the plunger flange of the syringe comprises a receiving head having a back flange connected to an elongated connecting member and a forward slotted flange connected to the elongated connecting member, the forward slotted flange is separated from the back flange by a space sufficient to accept the plunger flange.
 17. The adjustable dosage limiting device of claim 16, wherein the means for slidably interfacing to the barrel of the syringe comprises a barrel loop that slidably interfaces to the barrel of the syringe, the barrel loop is movably interfaced to the elongated connecting member.
 18. The adjustable dosage limiting device of claim 17, wherein the means for fixing the distance between the means for slidably interfacing to the barrel of the syringe and the means for attaching to the plunger flange is a locking mechanism.
 19. The adjustable dosage limiting device of claim 18, wherein the locking mechanism, after being locked, cannot be defeated without tools.
 20. The adjustable dosage limiting device of claim 18, wherein the locking mechanism comprises a tab that is hingedly interfaced to the barrel loop and has a wedge such that when the tab is moved to a locked position, the wedge locks to the elongated connecting member and the tab lays flush with a surface of the barrel loop, thereby the tab cannot be lifted without the use of tools. 